Carrier-Envelope Phase stabilized ultrafast lasers

With the new Legend Elite CEP, Coherent expands its family of Carrier-Envelope Phase stabilized ultrafast lasers.The Legend Elite CEP amplifies the ultrafast pulses generated by the Vitara CEP up to the millijoule level of energy required for applications such as high harmonics generation and attosecond science.

Based on the market leading Legend Elite platform, this new ultrafast regenerative amplifier includes an active feedback control to lock the phase velocity of the oscillating light field to the group velocity of the phase envelope. Thus, for ultra short pulses consisting of only a few optical cycles, the peak of the oscillating electrical field can be maximized under the phase envelope.

At the heart of the Legend Elite CEP is a non-linear interferometer. An octave-spanning optical spectrum is generated by focusing a small part of the amplifier beam on a sapphire plate. The red end of this spectrum is frequency-doubled and collinearly combined with the blue end of this same broad spectrum. The resulting spectral interference fringes are measured by a spectrometer and custom software uses this signal to measure, stabilize, and control the Carrier-Envelope Phase by making adjustments in the Legend amplifier.

The Legend Elite CEP now offers much higher power than any previously available system of this type. Specifically, the Legend Elite Duo CEP delivers up to 10 Watts of power, as well as higher repetition rates (up to 10 kHz), yet it does not require the complexity of cryogenic cooling of the gain medium, unlike systems offered by competitors.

With the Verdi pumped Vitara CEP and the Evolution pumped Legend Elite CEP, Coherent is the first and only company to offer a complete CEP-stabilized ultrafast amplifier system designed and built by a single manufacturer.